A cuckoo's migratory journey that has pleasantly surprised all scientists and officials at the Mongolia Cuckoo Project. One of their cuckoos named Onon has covered 26,000 kilometres in its round trip, across 27 border crossings involving 16 countries! Onon was tagged on 8 June 2019 and the bird returned today ie May 27 at the Khurkh Bird Banding Station.